21330246 has 64 divisors (see below), whose sum is σ = 51757056. Its totient is φ = 5728800.

The previous prime is 21330163. The next prime is 21330251. The reversal of 21330246 is 64203312.

It is a happy number.

21330246 is a nontrivial binomial coefficient, being equal to C(6532, 2).

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 68431 + ... + 68741.

It is an arithmetic number, because the mean of its divisors is an integer number (808704).

Almost surely, 2^21330246 is an apocalyptic number.

21330246 is the 6531-st triangular number and also the 3266-th hexagonal number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21330246, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25878528).

21330246 is an abundant number, since it is smaller than the sum of its proper divisors (30426810).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21330246 is a wasteful number, since it uses less digits than its factorization.

21330246 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 417.

The product of its (nonzero) digits is 864, while the sum is 21.

The square root of 21330246 is about 4618.4679277873. The cubic root of 21330246 is about 277.3311301112.

Adding to 21330246 its reverse (64203312), we get a palindrome (85533558).

It can be divided in two parts, 21330 and 246, that multiplied together give a triangular number (5247180 = T₃₂₃₉).

The spelling of 21330246 in words is "twenty-one million, three hundred thirty thousand, two hundred forty-six".